discordBots/cmd/dcimgproxy/main.go

package main

import (
	"github.com/disgoorg/disgo"
	"github.com/disgoorg/disgo/bot"
	"github.com/disgoorg/disgo/cache"
	"github.com/disgoorg/snowflake/v2"
	"io"
	"log/slog"
	"net/http"
	"os"
	"strings"
)

var (
	token       = os.Getenv("disgo_token")
	avatarCache map[snowflake.ID][]byte
)

var logger = slog.New(slog.NewJSONHandler(os.Stdout, nil))

func init() {
	avatarCache = make(map[snowflake.ID][]byte)
}

func main() {

	logger.Info("starting dealsbot...")

	mux := http.NewServeMux()

	client, err := disgo.New(token,
		bot.WithCacheConfigOpts(
			cache.WithCaches(cache.FlagsAll)),
	)
	if err != nil {
		logger.Error("error initializing disgo client", slog.Any("error", err))
		return
	}
	rest := client.Rest()

	mux.HandleFunc("/api/v1/discord/avatar/", func(w http.ResponseWriter, r *http.Request) {
		flake, err := snowflake.Parse(strings.TrimPrefix(r.URL.Path, "/api/v1/discord/avatar/"))
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		avatar, ok := avatarCache[flake]
		if !ok {
			user, err := rest.GetUser(flake)
			if err != nil {
				http.Error(w, err.Error(), http.StatusInternalServerError)
				return
			}
			avatarUrl := user.EffectiveAvatarURL()
			res, err := http.Get(avatarUrl)
			if err != nil || res.StatusCode != http.StatusOK {
				http.Error(w, err.Error(), http.StatusInternalServerError)
				return
			}
			// cache entry
			avatarCache[flake], err = io.ReadAll(res.Body)
			avatar = avatarCache[flake]
			if err != nil {
				http.Error(w, err.Error(), http.StatusInternalServerError)
				return
			}
		}
		w.WriteHeader(http.StatusOK)
		w.Header().Add("Content-Type", http.DetectContentType(avatar))
		_, _ = w.Write(avatar)
		return
	})

	err = http.ListenAndServe(":8080", mux)
	logger.Error("error from http listener", slog.Any("error", err))
}